1. Field of the Invention
This invention relates generally to the installation of dental prosthetic support implants, more specifically, to a method and device for engaging and removing a dental implant from its packaging, then transmitting rotational force from a drill, by hand or with a ratchet to the implant to thread the implant into bone tissue.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Dental prosthetic support implants are used to support prosthetic teeth on a patient's jaw bone. They are generally delivered in a sterile condition within a storage vial. To reduce risk of infection, the implants must be removed from the vial and installed in a manner that prevents contamination. Each implant generally includes a threaded shaft that is threaded into a pilot hole (osteotomy site) formed in a jaw bone through an opening formed by cutting and laying back a surgical flap of the gum tissue covering the bone. Once the implant has been installed, either at the time of implantation of at a later time, the gum tissue is closed around the implant with a stem of the implant protruding upward through the gum tissue. Once the gum tissue has healed around the implant, a prosthetic tooth is formed around or mounted on the protruding implant stem. Some implants also include hexagonal sockets formed axially downward into the respective top ends of their stems or hexagonal nuts formed integrally and axially upward from the respective top ends of their stems. The hexagonal configuration of such a socket or nut serves to prevent relative rotation of a prosthetic tooth that has been formed onto the stem and into or onto the socket. The socket or nut may be of any suitable shape, e.g., octagonal, triangular or a spline connection.
It is known to use a dental implant installation device to install an implant of this type by engaging and transmitting rotational force from a drill to the implant. For example, Intra-Lock, the assignee of the present invention, has produced a line of implant installation devices and implants known as the Conic Line Mount System. The Conic Line Mount device includes an elongated shaft and a hexagonal, tapered driver head disposed at a forward end of the shaft. The driver head is shaped to engage an axially internal hexagonal drive socket of a specially-designed dental implant, bypassing the prosthetic interface socket of the implant. The internal drive socket is formed in an axially inner wall of the outer prosthetic interface socket preventing damage to the prosthetic interface socket by providing an alternative driver engagement socket. An aft end of the shaft of the device includes a latch and shank configuration for releasably engaging a drill and transmitting turning forces from such drill to the device. However, the Conic Line Mount driver device can't positively engage and retain implants for transport to an osteotomy site. Implants are supported loosely on the Conic Line Mount driver and, if not supported by other means, can fall off the driver device. Also, torque loading is limited for this system because the tapered head of the Conic Line Mount driver device must engage generally parallel walls of the drive socket. Also, the diameter might not allow the driver to withstand heavy torque in dense bone, and the driver might break. That's why the conic driver has evolved to mimic the hex driver. The conic driver has an identical shape but is homothetically bigger.
U.S. Pat. No. 4,193,194 issued 18 Mar. 1980 to Dalise discloses a dental implant that includes a post having a base engageable within a natural tooth root and an upper end engageable within a generally cylindrical aperture in the base of a dental prosthesis. A circumferential kerf is formed into an outer circumferential surface of the post, and a corresponding kerf is formed in an inner circumferential surface of the aperture in the prosthesis. A resilient ring is received in and around and is retained by the circumferential kerf in the post. The kerf in the prosthesis receives the resilient ring when the denture is forced downward onto the implant post. The ring thus provides circumferential retention of the denture on the implant post.
A more effective implant installation device and method is needed—one that can positively engage, pick up, retain, and transmit rotational force to a prosthetic support implant to thread the implant into bone tissue without compromising sterility. The industry's answer to this need has been the use of an implant mount comprising a metal counterpart that retains an implant by engaging the implant's anti-rotational device (a hex nut, for example). Problems associated with such implant mounts include the cost of fabricating a complex machined part, the need to make it disposable, potential deformation of a prosthetic connection due to the high amount of torque that must be applied to the connection to drive the implant into dense bone, and the time needed to unfasten the mount once the implant has been placed.